Diagnostic System Check - Horns. Chevrolet PJJ 2001

For 1990-2009 cars

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

2. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to in Data Link Communications

2

1. Turn ON the ignition, with the engine OFF.
2. Attempt to establish communication with the body control module.

Does the scan tool communicate with the body control module?

Go to Step 3

Go to in Data Link Communications

3 | Select the body control module display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 4 | Go to Symptoms - Horns
4 | Does the scan tool display any DTCs which begin with a "U"? | Go to in Data Link Communications | Go to Step 5
5 | Does the scan tool display DTC B1000? | Go to in Body Control System | Go to Step 6
6 | Does the scan tool display DTC B1328? | Go to in Engine Electrical | Go to DTC List